Recent years have witnessed a significant growth in the popularity of dictation systems utilizing discrete recording media such as tape cassettes. The use of discrete media allows individual units of dictation to be recorded on separate media for individual access, for example, when a particular unit of dictation requires priority transcription. The advantage of individual access is particularly clear in comparison with prior art central dictation systems utilizing an endless loop of recording tape. In such systems, messages are recorded sequentially and can be transcribed out of order only if the transcribing person passes over the intervening material to reach the priority message and later rewinds the tape to transcribe the previously bypassed messages. This procedure may be considerably time-consuming and requires a special apparatus to prevent the bypassed messages from being inadvertently erased by subsequent message dictation before the bypassed messages are rewound for transcription.
The use of tape cassettes has a further advantage in that standard sizes such as the "C" size standard cassette or the "MC" microcassette, permit compatibility of the dictation system with other recording equipment such as portable dictation equipment and cassette tape recorders.
A significant problem with cassettes and other discrete media, however, is that the amount of dictation that can be recorded on a single cassette is limited. Thus, cassettes must be changed during dictation and a group of cassettes carrying a single long unit of dictation can become separated when transferred to a transcriber. Furthermore, no prior art dictation system has provided a capability for automatically providing access and reaccess to a number of cassettes, so that dictation can be recorded intermittently on each of several cassettes without manual handling of cassettes.
Standard sized tape cassettes have been utilized both in desk-top and central dictation/transcription systems. In one common form of desk-top system, both the dictating person and the transcribing person have similar desk-top units, each including a transducer head assembly for recording on or listening to a single tape cassette. Such a system requires a maximum of operator handling of individual tape cassettes. The cassettes must be carried from the dictating location to the transcribing location, and the dictating person must manually switch cassettes if it is desired to place an individual unit of dictation on a separate cassette. As work progresses, therefore, such a system generates a number of loose cassettes that must be catalogued and kept track of so that they are not lost and can be transcribed in the desired order.
The problem of handling individual cassettes becomes particularly acute for persons whose work requires intermittent attention to different types of work. For example, a person might need to dictate material related to several separate types of work each day, and further need to switch back and forth between types of work several times during the day. If dictation related to each type of work is to be recorded on an individual tape cassette, prior art dictation systems would require that the cassettes be manually switched in and out of the dictation apparatus. The dictating person would have to devote time and attention to organizing the loose tape cassettes so that they would be readily available the next time material was to be dictated related to particular types of work. Similarly, a person might have need of interrupting dictation to dictate a priority unit of dictation or to record a telephone call. Prior art dictation systems would again require handling and organizing of individual tape cassettes.
The prior art system shown in U.S. Pat. No. 4,113,994 utilizes a dual message recording and playback apparatus to reduce some of the manual delivery of tape cassettes between the dictating person and the transcribing person. A single unit located at the transcriber's desk contains two transport decks and associated record/listen transducers so that dictation may be recorded on one cassette while another is being transcribed. The dictating person has only a compact microphone and playback control. However, such an apparatus requires the dictating person to communicate with the transcribing person to manually provide a new tape cassette for dictation when such persons are simultaneously using the apparatus for dictation and transcription. Moreover, since a separate driving means and transducing means is required at each transport deck, considerations of size and cost place a limit upon the number of cassettes which can be made available without manual handling of cassettes.
Central cassette dictating apparatus, such as shown in U.S. Pat. No. 4,024,354, has provided apparatus for mechanically moving several individual tape cassettes into recording position in sequence. This allows the dictating person to move to a new tape cassette without handling cassettes, but restricts reaccess to cassettes containing previously recorded material. That is, it is impossible to intermittently accumulate dictation on a single cassette while also dictating on other cassettes. Thus, in order to provide for priority dictation and reaccess to partially completed dictation temporarily abandoned when the priority matter arose, it has been necessary to link two complete central dictation systems. Such a solution is not practical for a small office which cannot reasonably afford central dictation systems, but which requires a capability for priority dictation.
A further disadvantage of such prior art central cassette dictating systems is that the mechanical apparatus provided includes at least two expensive cassette changing mechanisms which move individual cassettes into and out of a recording position. In addition to being expensive, such mechanisms have tended to be unreliable since cassettes may become jammed while being removed from a pre-dictation storage location, carried and loaded onto a transport deck for recording, and then unloaded and carried to a post-dictation storage location.